The judge who will hear the capital murder case against accused Colorado theater gunman James Holmes said Thursday he will hold a hearing on the constitutionality of Colorado's insanity defense law in death penalty cases.

Arapahoe County District Judge Carlos Samour Jr. ruled that he will consider a defense motion that argues the statute is unconstitutional because it prevents Holmes from calling his own mental-health experts at sentencing if he refuses to cooperate with court-appointed psychiatrists.

Holmes appeared in court Monday with a thick, brown beard. He sat wordlessly and stared straight ahead as his attorney, Daniel King, told the judge that the defense has a mental illness diagnosis for the 25-year-old former medical student at University of Colorado-Denver.

Prosecutors said last month that they would seek the death penalty for Holmes.

Earlier in the case, defenders had asked then-presiding Judge William Sylvester to declare Colorado's insanity defense law unconstitutional because it compels a defendant to work with court-appointed psychiatrists, which may violate one's right against self-incrimination. Prosecutors objected to these claims.

But Samour, who was assigned the case last month, ordered both sides to present arguments on the issue at a hearing next week.

Court documents read:

"The Court orders the parties to confer... on the defendant's contention that [the insanity defense law] is unconstitutional to the extent it prevents him from calling any psychiatrist or other expert witness to provide evidence of his mental condition at the sentencing hearing if he fails to cooperate with psychiatrists and other personnel conducting the Court-ordered sanity examination."

Twelve people were killed and 58 wounded on July 20, 2012, at a midnight showing of the movie “The Dark Knight Rises” in the Denver suburb of Aurora. Holmes has been charged with 166 counts of murder, attempted murder, and other offenses in connection with the massacre.